Apraxia and spatial inattention dissociate in left hemisphere stroke.

Area of Science:

• Neuroscience
• Cognitive Psychology
• Neurology

Background:

• Cognitive function theories suggest left hemisphere dominance for motor control and right for spatial attention.
• Spatial attention deficits are more common after right-hemisphere strokes, while apraxia follows left-hemisphere strokes.
• Spatial attentional deficits after left hemisphere (LH) strokes are underreported.

Purpose of the Study:

• To investigate the relationship between spatial inattention and apraxia in LH stroke patients.
• To identify the neural underpinnings of spatial inattention and apraxia in LH stroke.
• To determine if spatial attention deficits are distinct from apraxic deficits in LH stroke.

Main Methods:

• Parallel analysis (PA) and voxel-based lesion-symptom mapping (VLSM) were applied.
• Neuropsychological assessment data from 74 LH stroke patients were analyzed.
• Component scores from PA were statistically mapped against lesion data.

Main Results:

• Apraxic and language comprehension deficits formed one independent component.
• Attention deficits were explained by a separate, independent component.
• Lesions in the left superior longitudinal fascicle (SLF) correlated with apraxic and language deficits.

Conclusions:

• Spatial attention deficits dissociate from apraxic and language comprehension deficits in LH stroke.
• Findings contribute to models of lateralized cognitive functions.
• LH stroke patients require systematic assessment for spatial attention deficits for rehabilitation planning.